“…For instance, guinea pig pups were known to exhibit a strong approach response to the rearing figure from shortly after birth (Gaston et al, 1969); there was better evidence for recognition and preference for the individual rearing figure as opposed to just odors associated with maternal diet (Breen & Leshner, 1977;Leon, Galef, & Behse, 1977;Pettijohn, 1979b;Gaston et al, 1969;Sluckin, 1968); the physiological maturity of the guinea pig pup ensured that vocalizations during maternal separation were not just responses to thermogenic challenge (Alexander, 1975); and unlike the case in rats (Henning, 1978;Levine, 2001), guinea pigs were known to not exhibit a profound suppression of HPA activity during much of the preweaning period (Dalle & Delost, 1974). For instance, guinea pig pups were known to exhibit a strong approach response to the rearing figure from shortly after birth (Gaston et al, 1969); there was better evidence for recognition and preference for the individual rearing figure as opposed to just odors associated with maternal diet (Breen & Leshner, 1977;Leon, Galef, & Behse, 1977;Pettijohn, 1979b;Gaston et al, 1969;Sluckin, 1968); the physiological maturity of the guinea pig pup ensured that vocalizations during maternal separation were not just responses to thermogenic challenge (Alexander, 1975); and unlike the case in rats (Henning, 1978;Levine, 2001), guinea pigs were known to not exhibit a profound suppression of HPA activity during much of the preweaning period (Dalle & Delost, 1974).…”